The present invention relates generally to oven door hinges. More specifically, the present invention relates to a counter-balance hinge for oven doors.
Large, free standing cooking appliances or ranges have been in use for many years. Typically, they include a horizontal surface with one or more heating elements or burners and a large cooking chamber or oven. The front side of the oven is generally provided with a door with which to either close off or access the oven. The door is generally pivotally attached adjacent to the oven sidewalls that partially define the oven such that when the door is opened, it extends forwardly and generally horizontally from a bottom surface of the oven. Often, when the door is opened, it is used to support heavy food items. Unfortunately, oven doors are also sometimes misused, as a step or a chair. As a consequence, manufacturing standards have been created which require hinged oven doors to be able to support a greater weight than would be normally expected in order to partially address such consumer misuses of such doors. As a further consequence, modem oven doors and their attendant hardware, such as hinges and the like, are designed with such potential misuse in mind. The end result is an oven door that is robustly constructed and quite heavy.
One drawback with such ranges is that some oven doors are merely hinged onto the range. If one is not careful when opening the oven door, the door might slam open, and damage the hinges, jarring items on the top of the range and, perhaps, knocking them to the floor in the process. In an attempt to address this drawback, springs (tension and compression) have been added between the range and the oven door to provide a force to counteract the weight of the oven door as it opened. This reduces, to one degree or another, unfettered door slamming. The springs are not always able to provide a true counterbalance, however, especially where the motion of the door is more-or-less neutral. One further drawback is that in some instances the spring is not strong enough to effectively counteract the weight and momentum of the oven door. The door still slams open in this situation, only with less force. Conversely, another further drawback was that in some instances, the spring is too strong and the oven door does not remain open and tends to slam shut without initiation by the user.
To address these drawbacks, manufacturers have taken several approaches with varying degrees of success. The approach taken in most cases involves changing the length of the spring. An approach that has been used with tension-spring type hinge assemblies is to provide one end of the spring with a hook, which may be positioned in one of a plurality of attachment holes in a tab that is attached to the oven door frame, thus changing the tension on the spring and force exerted by the spring on the oven door (see, for example, U.S. Pat. No. 3,150,658). Unfortunately, adjustment of the spring is limited to a series of discrete coarse steps, and like the above-mentioned springs, it is not always possible to strike a true counterbalance. A door may still open too quickly or close of its own accord. Moreover, such an arrangement requires the use of a very long spring and a hinge assembly that must be bolted or otherwise attached to an interior surface of the oven door. As such, it is not easily accessible for servicing or replacement.
Another drawback is that each hinge assembly is designed for a particular make and model of oven door having a predetermined weight. A hinge assembly designed for one make and model of an oven door is not easily interchanged with different makes or models of oven doors.
An approach that has been used with compression-type hinge assemblies is to apply springs of different spring constants or to change the length of the shaft using different, predetermined lengths of rods. This can also be achieved by providing one end of the shaft with a retainer, which may be positioned and retained on the shaft by a transverse locking pin that engages one of a series of transverse holes in the shaft (see, for example, U.S. Pat. No. 4,269,165). As with the aforementioned tension-type hinge assemblies, however, a drawback with such an arrangement is that adjustment of the compression spring is limited to a series of discrete coarse steps and it is generally not really possible to precisely adjust the length of the shaft to strike a true counterbalance.
Another drawback with such an arrangement is that the rods and the retainer are comparatively difficult and expensive to fabricate. In addition, they require specialized tools and skills to assemble and connect one to each other. In addition, in order to fully utilize such an arrangement, a great number of differently sized components would have to be stocked and readily made available.
It will be appreciated, then, that true counterbalancing of an oven door is difficult to achieve. It becomes significantly more difficult for hinges that are intended to be used on a variety of different makes and models of ranges, or hinges that are intended to be used in retrofitting applications. This is because many manufacturers of ranges do not fabricate their own oven door hinges. Rather, they obtain their hinges from third parties. Even though the oven doors of differently manufactured ranges may have the same exterior dimensions, they may not have the same weight. Thus, a situation can occur where a non-adjustable or coarsely adjustable hinge may perfectly counterbalance an oven door made by one manufacturer and fail to counterbalance a comparably sized oven door made by another manufacturer.
An additional drawback, common to both of the aforementioned types of hinges, is that a part of the hinge assembly projects through the interior surface of the oven door. Moreover, the amount of the extension changes as the door is moved between its open and closed positions. Therefore, the door must include a slot or aperture to accommodate this portion of the hinge assembly, and this can weaken the strength of the door. The slot can also become filled with debris, which may affect the operation of the door as well as prove difficult to clean.
It will be appreciated, therefore, that there is a need for an oven door hinge assembly that is lightweight and easy to manufacture. There is also a need for a door hinge assembly whose working components are able to fit substantially within predetermined spaces of an oven door and a range. There is also a need for an oven door hinge assembly that can be used with a variety of differently sized oven doors. And there is a need for a hinge assembly that can be modified so that it can be used to effectively counterbalance a range of oven doors manufactured for a variety of cooking appliances.
Briefly, the present invention comprises a hinge for use with a range having an oven and an oven door. The hinge comprises an arm and a hinge assembly that is pivotally attached thereto. The arm includes a first member and a second member, the first member being designed and arranged to be removably secured to the body of the range and the second member being designed and arranged to pivotally support the hinge assembly. The hinge assembly is preferably configured to be removably attached to the oven door and is also designed so that it allows the motion of the door to be substantially torque neutral as it moves between open and closed positions. The hinge assembly includes a biasing element and an adjustment member that provide a variable force that counterbalances the weight of the oven door.
More specifically, the first member of the arm is preferably configured to be inserted into and seated within a pocket or slot in the range in a restrained relation, preferably adjacent the lower edge of the oven. When the first member is in this seated position, the second member will extend outwardly and downwardly from the range by a distance that is sufficient to allow the hinge assembly and an attached door to pivot freely thereabout, such that the door can move between an oven sealing or closed position and an oven access or open position. The second member includes first and second transverse apertures that are collaterally aligned with respect to each other, and which pivotally support different portions of the hinge assembly.
The hinge assembly preferably comprises an elongated generally u-shaped housing, an elongated generally u-shaped link, a biasing element, and a generally u-shaped post with an adjustable stop. The elongated u-shaped housing has a first end and a second end, and comprises a rear wall, opposing sidewalls and an end wall. The first end of the housing is pivotally attached to the hinge arm by a pin or pintle, which is inserted through apertures in the sidewalls adjacent the first end of the housing and through the first aperture in the hinge arm. The first end of the housing also preferably includes a slot that extends partially up the rear wall and which is preferably configured to freely admit a portion of the hinge arm as the u-shaped housing is pivoted about the pin. The second end of the housing preferably includes a transverse end wall having a slot that is sized to freely admit the post and allow movement with respect thereto. The transverse end wall also serves to support one end of the biasing element.
The elongate u-shaped link of the hinge assembly also preferably has a first end and a second end, and further includes a front wall and opposing sidewalls. The u-shaped link is preferably pivotally attached to the hinge arm by a second pin or pintle, which is inserted through apertures in the sidewalls adjacent the first end of the u-shaped link and through the second aperture of the hinge arm, which is preferably spaced above and slightly to the rear of the first aperture. The u-shaped link is also preferably configured so that it may be positioned between the sidewalls of the u-shaped housing and movable with respect thereto in a constrained manner as the hinge assembly is rotated about the pintles. At the second end of the u-shaped link, the sidewalls are preferably provided with apertures or through holes that are configured to receive a crossbar, which is used to operatively connect the u-shaped link to the post.
The elongated, generally u-shaped post preferably has first end and second ends, and comprises a rear wall and opposing sidewalls. The sidewalls of the first end of the u-shaped post are preferably provided with slots or notches that are configured to engage the crossbar that is inserted into the sidewall apertures of the u-shaped link. The u-shaped post is also configured so that it may be positioned between the sidewalls of the u-shaped link. The sidewalls at the second end of the post likewise provided with apertures or through holes that are configured to engage a crossbar that operatively connects the post to the adjustment member. It will be appreciated that the above-mentioned generally u-shaped housing, link, and post are not only lightweight and strong, but are also less expensive to manufacture than solid core components.
The adjustment member preferably comprises an elongated shaft having first and second ends. The first end is preferably provided with a transverse aperture that is sized to accept the crossbar that is inserted through the apertures in the second end of the u-shaped post. The second end of the shaft is preferably threaded. Preferably, the adjustment member also comprises an adjustable stop that is used to vary the effective working length the u-shaped post. In use, a spring is positioned over the u-shaped post such that one end abuts the transverse end wall of the u-shaped housing. The adjustable stop is then positioned on the threaded end of the adjustment member and the nut is tightened or loosened to the desired degree. Thus, the hinge may be adjusted to counterbalance an oven door.
Accordingly, an object of the invention is to provide a hinge that can be adjusted to counterbalance an oven door.
Another object of the invention is to provide a hinge that can be easily installed on an oven, without the need for specialized tools or training.
Another object of the present invention is to increase the utility of an oven door hinge so that it may be used in a variety of differently sized oven doors.
A feature of the present invention is that the hinge can be infinitely adjusted between a predetermined range of values.
Another feature of the invention is that the hinge assembly can be removably attached to an oven door without having any parts protruding through the inner surface of the oven door.
An advantage of the hinge of the present invention is that it may be easily adjusted without the need for specialized tools of skills.
These and other objects, features and advantages of the present invention will become apparent from the following detailed description thereof taken in conjunction with the accompanying drawing, wherein like reference numerals designate like elements throughout the several views.